CVE-2025-25014: Elastic Kibana Prototype Pollution RCE

CVE-2025-25014 Overview

A Prototype pollution vulnerability in Kibana leads to arbitrary code execution via crafted HTTP requests to machine learning and reporting endpoints.

Critical Impact

This vulnerability can lead to complete system compromise due to arbitrary code execution potential.

Affected Products

• Elastic Kibana
• Elastic Kibana 8.18.0
• Elastic Kibana 9.0.0

Discovery Timeline

• Not Available - Vulnerability discovered by Not Available
• Not Available - Responsible disclosure to Elastic
• Not Available - CVE CVE-2025-25014 assigned
• Not Available - Elastic releases security patch
• 2025-05-06 - CVE CVE-2025-25014 published to NVD
• 2025-10-02 - Last updated in NVD database

Technical Details for CVE-2025-25014

Vulnerability Analysis

This vulnerability arises from improper handling of object structures in HTTP requests, leading to prototype pollution. An attacker can exploit this to execute arbitrary code within the Kibana environment.

Root Cause

The vulnerability is due to the lack of input validation in endpoints handling complex object structures, allowing attackers to inject properties into an object's prototype.

Attack Vector

The attack is executed over the network by sending crafted HTTP requests to vulnerable Kibana endpoints.

// Example exploitation code (sanitized)
const httpRequest = {
    method: 'POST',
    url: 'http://example.com:5601/api/reporting/generate',
    headers: {
        'Content-Type': 'application/json'
    },
    data: {
        '__proto__': {
            pollute: 'maliciousCode()'
        }
    }
};

Detection Methods for CVE-2025-25014

Indicators of Compromise

• Unusual HTTP requests with JSON payload keys like __proto__
• Unexpected changes in server behavior or outputs
• Execution of unexpected commands on the server

Detection Strategies

Utilize network monitoring tools to inspect HTTP traffic for suspicious patterns. Employ application logging to detect unusual property changes on JavaScript objects.

Monitoring Recommendations

Implement IDS/IPS solutions capable of detecting malicious HTTP payloads targeting known CVEs. Monitor logs for any attempts to perform prototype pollution via HTTP requests.

How to Mitigate CVE-2025-25014

Immediate Actions Required

• Update to the latest patched version of Kibana
• Implement strict input validation for incoming HTTP requests
• Disable unnecessary features in Kibana that could be exploited

Patch Information

Please refer to Elastic's advisory at Elastic Advisory for patch details.

Workarounds

While waiting for the official patch, consider deploying web application firewalls (WAF) to filter out malicious HTTP requests targeting the vulnerable endpoints.

# Configuration example for WAF
location /api/ {
    set $rule_0 0;
    if ($query_string ~* "\_\_proto\_\_") {
        set $rule_0 1;
    }
    if ($rule_0) {
        return 403;
    }
}